U.S. Pat. No. 4,736,866 (Leder et al.) discloses a transgenic non-human eukaryotic animal, preferably a mouse, whose germ cells and somatic cells contain an activated oncogene sequence introduced into the animal, or an ancestor of the animal, at an embryonic stage. In a preferred embodiment, the chromosome of the transgenic animal includes an endogenous coding sequence, most preferably the c-myc gene, which is substantially the same as the oncogene sequence. Transcription of the oncogene sequence is under the control of a promoter sequence different from the promoter sequence controlling transcription of the endogenous coding sequence or under the control of a synthetic promoter sequence. Gene fusions were made using the mouse myc gene and the MMTV LTR. The MMTV-myc plasmids were digested with SalI and EcoRI and separately injected into the male pronuclei of fertilized one-cell mouse eggs. The injected eggs were then transferred to pseudopregnant mice and allowed to develop to term. At 4 weeks of age, each pup born was analyzed using DNA taken from the tail in a Southern blot analysis. The Southern blot hybridizations showed that some of the founder mice retained the injected MMTV-myc fusion. The founder animals were then mated to uninjected animals and DNA of the resulting lines of transgenic offspring was analyzed. It was found that several lines of mice carried the MMTV-myc fusion. It is taught that the animals of the invention can be used to test a material suspected of being a carcinogen by exposing the animal to the material and determining neoplastic growth as an indicator of carcinogenicity. It is also taught that the invention can be used as tester animals for materials thought to confer protection against neoplasms.
Stacey et al., Nature, 332: 131-136 (1988) disclose transgenic mice bearing an engineered mutant pro.alpha.1(I) collagen gene. Two mutations were produced in a mouse COL1A1 genomic clone, both of which resulted in a substitution of a glycine residue at position 859 of the .alpha. 1(I) chain by either a cysteine or an arginine. Mutagenesis of the cloned gene was carried out by replacement of the wild-type DNA region between BstEII and SfiI restriction sites at positions 2623 and 2641 by double stranded synthetic oligodeoxyribonucleotides. The final constructs contained the complete coding region of the gene linked to one of four promoters: one-kilobase (kb), 2.5-kb and 3.7-kb fragments 5' of the mouse COLIA coding region, or the Maloney murine leukemia virus long terminal repeat promoter region. The mutant constructs were transferred into either NIH3T3 fibroblasts or into Mov13 homozygous fibroblasts which do not express the pro.alpha.1(I) collagen chain. Cultured cells expressing the mutant constructs produced type I collagen with the same biochemical characteristics as mutant collagens produced by cells from patients with perinatal lethal osteogenesis imperfecta. To determine whether the mutant constructs would generate a dominant phenotype similar to the human disease, DNA from the 3.7 kb-promoter Gly-Cys mutant cosmid was microinjected into fertilized eggs which were allowed to complete development in utero. It was found that none of the mice surviving birth was positive for the transgene. In contrast, almost all of the fetuses which died shortly before or after delivery carried copies of the mutant gene suggesting that the mutant gene exerts a dominant lethal effect.